kotlinx.coroutines

Class CoroutineContextKt

kotlinx.coroutines.CoroutineContextKt

public class CoroutineContextKt

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEBUG_PROPERTY_NAME Name of the property that controls coroutine debugging. See newCoroutineContext.
static java.lang.String	DEBUG_PROPERTY_VALUE_AUTO Automatic debug configuration value for DEBUG_PROPERTY_NAME. See newCoroutineContext.
static java.lang.String	DEBUG_PROPERTY_VALUE_OFF Debug turned on value for DEBUG_PROPERTY_NAME. See newCoroutineContext.
static java.lang.String	DEBUG_PROPERTY_VALUE_ON Debug turned on value for DEBUG_PROPERTY_NAME. See newCoroutineContext.
static java.lang.String	IO_PARALLELISM_PROPERTY_NAME Name of the property that defines the maximal number of threads that are used by CoroutineContextKt.getIO coroutines dispatcher.

Method Summary

Modifier and Type	Method and Description
static CoroutineDispatcher	getDefaultDispatcher() The default class CoroutineDispatcher that is used by all standard builders like BuildersKt.launch, DeferredKt.async, etc if no dispatcher nor any other ContinuationInterceptor is specified in their context.
static CoroutineDispatcher	getIO() The class CoroutineDispatcher that is designed for offloading blocking IO tasks to a shared pool of threads.
static NonExistentClass	newCoroutineContext(NonExistentClass context, Job parent) Creates context for the new coroutine. It installs DefaultDispatcher when no other dispatcher nor ContinuationInterceptor is specified, and adds optional support for debugging facilities (when turned on).
static NonExistentClass	newCoroutineContext(NonExistentClass context) Creates context for the new coroutine. It installs DefaultDispatcher when no other dispatcher nor ContinuationInterceptor is specified, and adds optional support for debugging facilities (when turned on).

Field Detail

DEBUG_PROPERTY_NAME

public static java.lang.String DEBUG_PROPERTY_NAME

Name of the property that controls coroutine debugging. See newCoroutineContext.

DEBUG_PROPERTY_VALUE_AUTO

public static java.lang.String DEBUG_PROPERTY_VALUE_AUTO

Automatic debug configuration value for DEBUG_PROPERTY_NAME. See newCoroutineContext.

DEBUG_PROPERTY_VALUE_ON

public static java.lang.String DEBUG_PROPERTY_VALUE_ON

Debug turned on value for DEBUG_PROPERTY_NAME. See newCoroutineContext.

DEBUG_PROPERTY_VALUE_OFF

public static java.lang.String DEBUG_PROPERTY_VALUE_OFF

Debug turned on value for DEBUG_PROPERTY_NAME. See newCoroutineContext.

IO_PARALLELISM_PROPERTY_NAME

public static java.lang.String IO_PARALLELISM_PROPERTY_NAME

Name of the property that defines the maximal number of threads that are used by CoroutineContextKt.getIO coroutines dispatcher.

See Also:

CoroutineContextKt.getIO

Method Detail

getDefaultDispatcher

public static CoroutineDispatcher getDefaultDispatcher()

The default class CoroutineDispatcher that is used by all standard builders like BuildersKt.launch, DeferredKt.async, etc if no dispatcher nor any other ContinuationInterceptor is specified in their context.

It is currently equal to class CommonPool, but the value is subject to change in the future. You can set system property "kotlinx.coroutines.scheduler" (either no value or to the value of "on") to use an experimental coroutine dispatcher that shares threads with CoroutineContextKt.getIO dispatcher and thus can switch to CoroutineContextKt.getIO context without performing an actual thread context switch.

See Also:

class CoroutineDispatcher, BuildersKt.launch, DeferredKt.async, ContinuationInterceptor, class CommonPool, CoroutineContextKt.getIO, CoroutineContextKt.getIO

getIO

public static CoroutineDispatcher getIO()

The class CoroutineDispatcher that is designed for offloading blocking IO tasks to a shared pool of threads.

Additional threads in this pool are created and are shutdown on demand. The number of threads used by this dispatcher is limited by the value of "kotlinx.coroutines.io.parallelism" (IO_PARALLELISM_PROPERTY_NAME) system property. It defaults to the limit of 64 threads or the number of cores (whichever is larger).

See Also:

class CoroutineDispatcher

newCoroutineContext

public static NonExistentClass newCoroutineContext(NonExistentClass context,
                                                   Job parent)

Creates context for the new coroutine. It installs DefaultDispatcher when no other dispatcher nor ContinuationInterceptor is specified, and adds optional support for debugging facilities (when turned on).

Debugging facilities: In debug mode every coroutine is assigned a unique consecutive identifier. Every thread that executes a coroutine has its name modified to include the name and identifier of the currently running coroutine. When one coroutine is suspended and resumes another coroutine that is dispatched in the same thread, then the thread name displays the whole stack of coroutine descriptions that are being executed on this thread.

Enable debugging facilities with "kotlinx.coroutines.debug" (DEBUG_PROPERTY_NAME) system property , use the following values:

• "auto" (default mode, DEBUG_PROPERTY_VALUE_AUTO) -- enabled when assertions are enabled with "-ea" JVM option.

• "on" (DEBUG_PROPERTY_VALUE_ON) or empty string -- enabled.

• "off" (DEBUG_PROPERTY_VALUE_OFF) -- disabled.

Coroutine name can be explicitly assigned using class CoroutineName context element. The string "coroutine" is used as a default name.

See Also:

ContinuationInterceptor, class CoroutineName

newCoroutineContext

public static NonExistentClass newCoroutineContext(NonExistentClass context)

Creates context for the new coroutine. It installs DefaultDispatcher when no other dispatcher nor ContinuationInterceptor is specified, and adds optional support for debugging facilities (when turned on).

Debugging facilities: In debug mode every coroutine is assigned a unique consecutive identifier. Every thread that executes a coroutine has its name modified to include the name and identifier of the currently running coroutine. When one coroutine is suspended and resumes another coroutine that is dispatched in the same thread, then the thread name displays the whole stack of coroutine descriptions that are being executed on this thread.

Enable debugging facilities with "kotlinx.coroutines.debug" (DEBUG_PROPERTY_NAME) system property , use the following values:

• "auto" (default mode, DEBUG_PROPERTY_VALUE_AUTO) -- enabled when assertions are enabled with "-ea" JVM option.

• "on" (DEBUG_PROPERTY_VALUE_ON) or empty string -- enabled.

• "off" (DEBUG_PROPERTY_VALUE_OFF) -- disabled.

Coroutine name can be explicitly assigned using class CoroutineName context element. The string "coroutine" is used as a default name.

See Also:

ContinuationInterceptor, class CoroutineName